Dendrobium gracilicaule is accepted species in  the family Orchidaceae  subfamily: Epidendroideae, tribe: Dendrobieae, subtribe: Dendrobiinae,  
Genus Dendrobium   section: Dendrocoryne 
Infraspecific taxa recognized within Dendrobium gracilicaule: infraspecific taxa
This species is found in S. Queensland to New South Wales and SW. Pacific.